LECTURE 7 Flashcards
MORPHINE
ALLOWS FOR DOSE-RELATED ANALGESIA AND **INCREASED PAIN TOLERANCE
CAN CAUSE EUPHORIA; HOWEVER, IF ADMINISTERED TO A PERSON WHO IS PAIN FREE, IT CAN CAUSE DYSPHORIA, ANXIETY, MENTAL CLOUDING
SIDE EFFECTS - RESPIRATORY DEPRESSANT, COUGH SUPPRESSANT
MORPHINE BIPHASIC DOSE-DEPENDENT EFFECT ON BODY TEMPERATURE
LOW DOSE - CAUSES A DECREASE IN BODY TEMPERATURE
HIGH DOSE - CAUSES AN INCREASE IN BODY TEMPERATURE
HYDROMORPHONE
(DILAUDID)
ORAL ADMINISTRATION (15-30 MIN)
IV ADMINISTRATION (5 MIN)
RAPIDLY ABSORBED, HIGH 1ST PASS METABOLISM
**3-5X MORE POTENT WHEN GIVEN ORALLY AS MORPHINE (NO INACTIVE/ACTIVE METABOLITES - NO NEED TO WORRY ABOUT PATIENT TO PATIENT VARIABILITIES)
USED FOR MILD TO STRONG PAIN IN HOSPITALS
PHARMACOKINETICS SIMILAR TO MORPHINE
FENTANYL
MANY DIFFERENT WAYS OF ADMINISTERING
ORAL, BUCCAL (5-15 min.), IM (7-8 min.), NASAL SPRAY, IV (immediate), TRANSDERMAL (6h), LOLLIPOPS, LOZENGES
HIGHLY LIPOPHILIC - GETS THROUGH MEMBRANES QUICKLY
80x ANALGESIC POTENCY OF MORPHINE, 10x ANALGESIC POTENCY OF HYDROMORPHONE
**USED FOR BREAKTHROUGH PAIN IN COMBINATION W/ ANOTHER OPIOID FOR CHRONIC PAIN
**HIGH ABUSE POTENTIAL
**SHORT TERM RELIEF
INTERMEDIATE OPIOIDS
**OXYCODONE - SIMILAR EFFICACY TO MORPHINE BUT HAS BETTER ORAL BIOAVAILABILITY (THEBAINE DERIVATIVE)
METHADONE - HIGH POTENCY, LONG DURATION OF ACTION, GOOD ORAL BIOAVAILABILITY, A LOT OF INTER-PATIENT VARIABILITY
**USED FOR OPIOID ADDICTION
BUPRENORPHINE - SL/TD ADMINISTRATION, MU OPIOID EFFICACY AGONIST AND HAS KAPPA ANTAGONIST ABILITIES (GOOD FOR ANALGESIA AND OPIOID ADDICTIONS)
WEAK OPIOIDS
TRAMADOL - WEAK MU AGONIST W/ 5-HT AND NOREPINEPHRINE REUPTAKE INHIBITION (GOOD ORAL BIOAVAILABILITY)
**COMBINES ANTIDEPRESSANT REACTIONS W/ OPIOID REACTIONS
TAPENTADOL - MU AGONIST W/ NE REUPTAKE INHIBITION (B/C NO SEROTONIN REUPTAKE INHIBITION AND STRONG NE REUPTAKE INHIBITION W/ SAME MECHANISM AS COCAINE AND AMPHETAMINE => **HIGH POTENTIAL FOR ABUSE)
CODEINE METABOLISM
CATALYZED TO MORPHINE BY CYP2D6 ENZYME
POLYMORPHISMS IN CYP2D6 =>
1.) INABILITY TO CONVERT CODEINE TO MORPHINE IN 10% OF CAUCASIANS
2.) ULTRA-RAPID CATALYSIS OF CODEINE TO MORPHINE AND AN INCREASE IN SENSITIVITY IN 4-5% OF US POPULATION AND 16-28% OF NORTH AFRICANS, ETHIOPIANS, AND ARABS
NALOXONE (NARCANE)
OPIATE ANTAGONIST - REVERSES RESPIRATORY EFFECTS OF OPIOID AGONISTS
PHARMACOKINETICS =
IM, SUBQ = 2-5 MIN., INHALATION ~5 MIN., INTRANASAL 8-13 MIN., IV ~2 MIN.
DURATION OF ACTION = 30-120 MIN. (REPEATED DOSES ARE USUALLY NEEDED)
REVERSES ALL EFFECTS OF OPIOID AGONISTS AND BLOCKS MU, KAPPA, AND DELTA RECEPTORS
ARACHIDONIC ACID
EICOSANOID PRECURSOR - RELEASED FROM PHOSPHOLIPID MEMBRANE => EICOSANOID SYNTHESIS
OXYGENATED BY CYCLOOXYGENASE, LIPOOXYGENASE, OR CYTOCHROME P450 TO => EICOSANOID PRODUCT
MOST IMPORTANT PRODUCT = PROSTANOIDS - MAINTAIN KEY ROLES IN PAIN SENSING
PROSTANOIDS
PRODUCED BY OXYGENATION BY 2 ENZYMES - COX-1 AND COX-2
1.) POSTAGLANDIN
2.) PROSTACYCLIN
3.) THROMBOXANE (KEY ROLE IN BLOOD CLOTTING)
ALL ARE LOCALLY PRODUCED FOR IMMEDIATE ACTION
COX-1
CONTINUOUSLY MADE AND AVAILABLE TO THE BODY 24/7
PROMOTES CLOTTING, PROTECTS GI MUCOSA, MAINTAINS KINDEY VASODILATION
I.E. ALL REGULAR PHYSIOLOGICAL FUNCTIONS
COX-2
INDUCIBLE BY VARIOUS INSULTS AND PRODUCTS INVOLVED IN INFLAMMATION/CANCER
COX-2 INHIBITORS CAN BE TAKEN FOR ARTHRITIS
ACTIVATED BY LOCAL INFLAMMATION, MODULATE PAIN, PERCEPTION AND PROMOTES FEVER
NSAIDS / ASPIRIN
NON-STEROIDAL ANTI-INFLAMMATORY DRUGS
BLOCK ENZYMES (SELECTIVELY, NON-SELECTIVELY, REVERSIBLY, IRREVERSIBLY)
INVOLVED IN SYNTHESIS OF PROSTAGLANDIN-2 CYCLOOXYGENASE AND PROSTANOID
MECHANISM OF ACTION OF NSAIDS/ASPIRIN
DECREASED VASODILATION BY PRG-2 WHICH MEANS LESS VASODILATION AND LESS EDEMA
LESS SENSITIZATION OF NOCICEPTIVE NERVE ENDINGS TO BK/5-HT MEDIATORS (IF NO PRG-2 PRODUCED THEN CAN’T RESPOND TO BK/5-HT STIMULUS)
ANTIPYRETIC - DUE TO DECREASE IN PRG-2 RESPONSE TO IL-1
ANTIPLATELET - (IR)REVERSIBLE (ASPIRIN) INHIBITION OF THROMBOXANE SYNTHESIS ; HOWEVER’ WHERE OTHER TISSUES CAN JUST MAKE MORE THROMBOXANE, PLATELETS AREN’T CELLS AND TAKE A LONG TIME TO MAKE MORE THROMBOXANE
ADVERSE EFFECTS OF COX-1 INHIBITION
GASTRIC ULCERS
BLEEDING
ACUTE RENAL FAILURE
DUE TO FAILURE TO MAKE PRG